simon2579/iStockBy BILL HUTCHINSON, ABC News

(SAN FRANCISCO) -- A shortage in the supply of COVID-19 vaccination doses has prompted health officials in San Francisco to temporarily close two mass inoculation sites, authorities said.

Mary Ellen Carroll, executive director of the San Francisco's Department of Emergency Management, said mass vaccination sites at the city's Moscone Center convention hall complex and one at San Francisco City College have been put on pause.

"We've made progress and it really is hard to pause operations. None of us want to do it but it is temporary, we know we will get more vaccine, and it does appear to be a supply chain production issue," Carroll told ABC station KGO-TV in San Francisco.

She said the Moscone Center site will close for at least a week and will reopen when the vaccine supply is sufficiently replenished. She said the City College mass vaccination site will also close until Friday, at which time only second doses will be given.

San Francisco's COVID-19 Joint Information Center said the city has the capacity to administer more than 10,000 vaccines per day but lacks the supply.

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